Residential homeowners need to be aware of the impact that Mediterranean fruit fly (Medfly) can have on their own home-grown fruits and vegetables:
A great variety of dooryard fruits and vegetables are at risk. Some examples are grapefruit, orange, mandarin, hot pepper, bell pepper, strawberry, avocado, mango,fig, guava, plum, papaya, peach, pomegranate, soursop, and many others.
Medfly maggots bore throughout the fruit and render it unfit for human consumption. Adult females lay an average of about 10 eggs into each healthy fruit or vegetable while still on the tree or on the vine. Each egg hatches into a white maggot that grows up to 1/4 inch in length.
There is no easy control of Medfly. Eggs and maggots, once inside the fruit or vegetable, are not killed by insecticides, so they continue to hatch, feed and grow. In areas where Medfly has become established, growers typically resort to weekly insecticide spraying of fruiting trees and garden plots to kill adults. An alternative is to physically bag individual fruits before they ripen to prevent female Medfly from laying eggs.
Medfly can breed prolifically and persist year-round in most parts of Central and South Florida. Medfly growth and development proceed at temperatures above 50°F. The ideal temperature is about 79°F at which Medfly population sizes typically increase 10- to 100-fold every 30 days!
Expect higher fruit and produce costs. Increased costs from crop loss, insecticide treatment, fumigation or other post-harvest treatment against Medfly will be passed on to consumers. An alternative is to neglect local economies and spend our dollars on produce from other states or countries.
Much has been discussed concerning the impact of Medfly on the Florida citrus industry as if this segment of the Florida population were the only potential victim should Medfly colonize the state. Consider the following statements concerning the impact on residential homeowners in Hawaii after Medfly colonization (Back and Pemberton 1918):
"The residents of Honolulu are justly proud of their magnificent vegetation and have taken great pleasure in growing an unusually large assortment of trees and shrubs upon their town properties. An inventory of such trees and shrubs ...[yielded] an average of 6.5 trees per dooryard capable of supporting the fruit fly. ... in tropical and semitropical climates this fruit fly is capable of becoming a pest of prime importance and, as in the Hawaiian Islands, may be classed as the most important insect check to horticultural development. ...practically every fruit crop of value to man is subject to attack. ... At the present time the infestation of edible fruits in littoral Hawaii is general and about as severe as could be expected.
It is true that the Florida citrus industry has a great deal at stake should the Medfly establish here. About 25% (nearly $3.4 billion) of total cash receipts for all agricultural commodities (including livestock) in Florida comes from citrus. Note, however, that equally at risk is another 12% of the economy contributed by fruits, vegetables, melons and berries such as pepper, tomato, strawberry, mango, and avocado. Those areas greatest affected include Hillsborough County with the greatest number of individual farms (2,760), big and small, of any county in the state followed by Polk County with 2,294 farms. Both counties have huge acreages devoted to orange, tomato, peppers, strawberry, grapefruit and other crops at high risk of Medfly infestation. Over 90,000 Floridians are directly employed as farm workers. Many thousands of others are employed in other agriculture-related jobs including processing and distribution of fruit and vegetable products (1996 Florida Agricultural Facts).
REFERENCES
1996 Florida Agricultural Facts. Florida Dept of Agriculture and Consumer Services, Tallahassee FL, 72 pp.
Back, E.A. & C.E. Pemberton. 1918. The Mediterranean fruit fly in Hawaii. USDA Bulletin No. 536, 118 pp.